package com.hbpu.encap.final_;

public class FinalExercise {
    public static void main(String[] args) {
        Circle circle = new Circle(2.4);
        System.out.println("圆的面积为：" + circle.area());
    }
}

class Circle {
    private static double radius;
    private static double PI = 3.14;

    public Circle(double radius) {
        Circle.radius = radius;
    }

    public double area() {
        return PI * radius * radius;
    }
}

class Test extends Circle {

    public Test(double radius) {
        super(radius);
    }
}